Press roll drive



May 9, 1944 l.. HoRNBsTl-:L

PRESS BULL DRIVE 3 Sheets-Sheet l Filed May a, 1941 May 9, `1944 L. HoRNBos-ral. 2,348,345

PRESS ROLL DRIVE Filed May 8, 1941 3 Sheets-Sheet 2 Hs ff May 95 1944 l.. HoRNBosTEl.

PRESS ROLL DRIVE Filed May 8, 1941 3 Sheets-Sheet 5 Z ZVEI Z v Lon/o Hoen/6067x611..

Patente'd May 9, 1944 PRESS ROLL DRIVE Lloyd Hornbostel, Beloit,

Iron Works, Beloit, Wis

consin Wis., asslgnor to Beloit a corporation of Wis- Application May 8, 1941, Serial No. 392,443

2 claims.

This invention relates to the driving of press rolls of a paper making machine to divide the driving effort going .to coopera-ting or adjacent rolls so as to obtain any desired division of driving effort. More particularly, this invention relates to the tapping oi of any desired amount of driving effort from one roll of the press roll assembly to help drive anothervroll of the as sembly.

In accordance with this invention, one of the rolls of a press roll assembly is directly driven from a prime mover while one or more of the other rolls of the assembly, orof an adjacent assembly, is driven through an electric slip coupling having no rubbing parts and being controllable to vary the driving effort or shaft twist that goes through the coupling by a mere simple adjustment of the amount of current fed to the coupling.

It is thus now possible, in accordance with this invention, to positively drive the bottom roll of a two roll vertical press and to simultaneously supply the top roll of the press with any desired proportional amount of driving effort ap,

plied to the bottom roll, to directly drive an end roll of a three roll horizontal press assembly and to supply any amount of positive driving action to the other end roll of this assembly, or to positively drive one bottom roll of a vertical press while applying-any desired amount of driving effort to an adjacent bottomvroll of another vertical press acting on the same felt.

An important feature of this invention resides in the possible use of a slip coupling asa clutch permitting a. cut-off of any of the clutch driven rolls;k Thus, in thepress roll drives of this invention electric slip couplings are provided to give a helping drive effect and to act as a cutoff coupling. y

A feature of the coupling is that it has no rubbing or wearing parts and acts on a magnetic slip principle caused by inducement of a magnetic flux between the driving and driven parts. Excitation of the driven parts controls the degre'e of slippage. If the driven part is not excited or electrically energized, the part is uncoupled. If the driven part is partially energized the clutch will slip an amount directly dependent upon the degree of excitation. Even if the driven part is fully energized, some slippage will occur.

Another feature ofthe invention resides in the fact that increased loading of the clutch driven roll resultsin increased application of driving torque to the roll so that while the speed of the roll may slow down, the torque increases to compensate for the increased load. The faster the coupling slips, the more driving effort or shaft twistV is transmitted.

Another feature of the press roll drives of this invention resides in provision of an electrical slip coupling to operate the coupling driven roll at a slower speed than the direct driven roll, so as to obtain an ironing'or smoothing effect on the paper.

It isthen an object of this invention to provide press roll drives for paper making machines enabling any desired division of driving effort to the press rolls.

Another object of the invention is to provide an electric slip coupling drive as a means to vary the speeds of press rolls.

A further object of the invention is to provide a helper drive for press rollassemblies which is simply regulated to vary the division of driving effort between the rolls.

A further object of this invention is to provide -a press roll drive assembly utilizing electric slip couplings with no rubbing parts, both as helper drive units and as cut-off coupling units.

Other and further objects and features of the invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of preferred examples, illustrate three embodiments of the invention.

On the drawings:

Figure 1 is an end elevational, somewhat diagrammatic, view of a two. roll vertical press assembly for a paper making machine;

Figure 2 is a fragmentary side elevational view of the two roll press shown in Figure 1 and illustrating the driving assembly in accordance with this invention;

Figure 3 is a side elevational view, with parts ,broken away and shown in vertical cross-section.

of an eddy current slip coupling or dynamatic clutch used in the drive assembly shown in Figure 2;

Figure 4 is a view of the clutch taken along the line IV-IV of Figure 3;

Figure 5 is an'end elevational, somewhat diagrammatic, view of a three roll horizontal. press roll assembly for a paper making machine;

Figure 6 is a fragmentary top plan view of the three roll press assembly shown in Figure 5 and illustrating the drive for the first and third rolls of the assembly in accordance with this invention;

Figure 7 isan end elevational, somewhat diagrammatic. view of two adjacent presses of a paper machine; and

'Figure 8 is a fragmentary top plan view of the bottom rolls of the two adjacent presses shown in Figure 7 and illustrating the drive for said rolls in accordance with this invention.

As shown on the drawings:

In Figures 1 and 2, the reference numeral I0 designates generally a vertical press assembly composed of a bottom roll II and a cooperating top roll I2 with a felt F passing through the nip between the rolls for conveying a web W through the assembly. The bottom roll II has an axle I3 joined through couplings I4 and a shaft I5 to a drive shaft I6 projecting from a, gear box I1. The drive shaft I6 of the gear box is actuated by a pulley I8 driven by a belt I9 from a prime mover (not shown). The top roll I2 has an axle 20 joined through universal joints 2I with a shaft 22 driven by the driven part of an electric slip coupling. The electric-slip coupling, indicated generally by the reference Vnumeral 23, is driven by a shaft 24. The shaft 24, in turn, is driven through gears 25 and 26 from the shaft I6 of the gear box. ,i f In this manner the bottom roll II is directly coupled to a prime mover, while the top roll I2 is driven from the in-shaft tothe bottom roll through an electric slip coupling which controls the amount of driving effort applied to the top roll. l

. As shown in Figures 3 and 4, the electric slip coupling l23 is composed of a metal armature drum 21 having interior transverse slots 28 in spaced relation around the inner periphery thereof to denne inwardly projecting transverse teeth 29. 'The armature drum 21 has a hub 21asecured on the shaft 24. l

A magnetic spider is mountedwithin the armature drum 21 and has a hub' 30a secured on the shaft 22.

The spider30 has a rim portion 3l with upstanding end flanges 32`providing a chamber 33 in which is wound an annular coil 34 of wire. The coil 34 is covered with a non-magnetic plate 35,` and the anges 32 are transversely grooved as at 36 (Figure 4) to provide a plurality of radially extending transverse `teeth 31 around the periphery of the spider. The teeth 31on the spider and the teeth 29 on the armature drum' do not engage.

A pair of electric sl'ip` rings 38 and 39 are mounted in insulated relation on the hub 30a of the spider. One end 34a of the coil is connected to the ring 38. The other end 34h of the coil is connected to the ring 39.

The rings 38 and 39 rotate with the spider, since they are ilxedly secured on the hub thereof.

Brushes 40 and 4I contact the slip rings 38 and 39 in electrical contact therewith. These brushes 40 and 4I are stationary and are included in an electrical circuit 42 including a source 43 of direct current, a rheostat 44, and an ammeter 45.

The electric slip coupling or dynamatic clutch 23 thus contains no frictionally engaging coupling members. The coupling effect is obtained by energization of excitation of the coil 34 in the spider 30 to create a magnetic field around the coil l34. The magnetic eld induces eddy currents in the varmature drum and eld when there is any relative movement between them. The degree of excitation of the coil determines the amount of slippage of the parts. When the coil is deenergized, the drum 21 will rotate freely around the spider without turning the spider therewith. When the coil is energized, the magnetic flux will drag the spider with the drum. However, a certain amount of slippage will always occur within the coupling, and the faster the coupling slips the more driving effort or torque is applied to the spider.

In the assembly shown in Figure 2, the top roll I2 can receive an amount of driving eiort from the in-shaft to the bottom roll in accordance with the amount of energization or excitation of the coil in the slip coupling 23. The rheostat 44 can be set so that the roll I2 will operate at the same speed as the roll II or at a slower speed than the roll II. In other words,

a dragging eiect can be maintained on the web W by driving the roll I2 slower than the roll II. The roll I2 can be allowed to run free from any driving mechanism by merely deenergizing the coil in the slip coupling.

Therefore, in vertical press assemblies such as are shown in Figures 1 and 2, the present invention makes possible the direct driving of one of the rolls of the assembly and the application of any desired amounts of driving eiort to the other roll of 'the assembly.

As shown in Figures 5 and 6, the horizontal press roll assembly 50, composed of a middle roll rotatably mounted in xed bearings such as 52 on a frame 53 and end rolls 54 and 55 on each 'side of the roll 5I rotatably mounted in bearings 56 on swingable arms 51 which are pivoted to the frame 53, receives a web W downwardly through the nrst nip between the rolls 5I and 54, thence around the bottom of the roll 5I and upwardly through the nip between the rolls 5| and 55.

lDraw bolt means 58 are provided for swinging the rolls 54 and 5 5 against the middle roll 5I to bring all three rolls in substantial horizontal alignmentand to create pressures in the nips betweenthe rolls. Endless looped felts FI and F2 are trained through the nips and around guide rolls for protecting the web against crushing in the nips. r

As shown in Figure 6, a pulley M driven from a prime mover such as an electric motor (not shown) drives gears 5 9 in a gear box 6I!l to rotate an in-shaft 6I coupled through universal joints 62 with the third roll 55. The roll 55 is` thus 'directly driven from the motor.

The in-shaft Iilv projects through the other side of the 'gear box 60 to drive a'pulley 63 for propelling a belt 64 to drive a pulley 65 on an auxiliary shaft 66. The auxiliary shaft 66 drives the armature drum of an electric slip'coupling such as 23 described above. This electric slip coupling, in turn, drives a shaft `iiI coupled through universal joints 68 to the first roll 54.

'I'he electric slip coupling 23 in the drive assembly shown in Figure 6 therefore makes possible the adjustment of the amount of driving effort to the ilrst roll 54 of the three roll press and also makes possible the use of the clutch as a cut oif coupling if for any reason the rolls 5I and 55 of the press are to be used separately. While the third roll 55 is directly coupled to the motor and, in turn, serves to drive the rolls 5| and 54 through the nips, because of the nip engagement therebetween a certain amount of slippage would progressively occur and the rst `roll might have an undue dragging effect on the It the load on the i'irst roll is changed due to a tightening up oi.' the drawing means Il to increase the nip pressure between the rolls. there would be a tendency to make the clutch slip faster. but at the same time the driving torque imparted to the roll would be increased. Ii it is then desired to bring the roll up to speed, all that is necessary is an adjustment of the rheostat 44 to decrease the slippage of the clutch.

In the embodiment shown in Figures '1 and 8, the reference character 10 designates generally a press roll section of a paper machine composed of two vertical presses 1i and 12. 'I'he vertical press 1i contains a top roll 13 and a bottom roll 14. The press 12 contains a top roll 15 and a bottom roll 16. A `felt F is trained around guide rolls through both presses-1I and 12 to convey a web W through the presses.

As shown in- Figure 8, the lower roll 16 of the second press 12 is coupled through couplings 11 with the in-shaft 18 of a gear box 19 which is driven by pulley M from a prime'mover, (not shown). The shaft 18 extends through the other side of the gear box 19 and drives a pulley l0 connected through a belt 8| to a pulley 82 on a shaft 83 which drives the armature drum of an electric slip coupling or dynamatic clutch 23 such as is described above.

The clutch 23 in Figure 8, in turn, drives the iii-shaft 84 to the bottom roll 'M of the first press 1I. The amount of slippage in the clutch 23 is controlled by the excitation circuit l2.

The drive assembly illustrated in Figures 7 and 8 makes possible the driving of the first press 1i entirely by the felt F from the second press 12 by deenergizing the coll in the electric coupling 23 so as to uncoupie the shafts 83 and Il or any desired amount of driving eiort can be applied to the first press 1| from the second press 12 by energizing the coil ofthe slip clutch any desired amount.

If the nap of the felt indicates that the first press 1i has an excessive dragging eiect, the rheostat 44 controlling the excitation circuit can be reset to supply more current to the slip clutch coil thereby decreasing the slippage of the coil and speeding up the first press to the speed of the second press or any speed under the speed ci.' the second press.

From the above descriptions, it will be clearly understood that the press roll drives o! this invention al1 include electric slip couplings or dynamatlc. clutches operating on a direct current excitation principle for helping the drive of one roll from the drive of another roll or ior uncoupling the helper drive.

I claim as my invention:

1. A drive assembly for the press rolls of a paper machine press of the type having press rolls in cooperating pressure driving relation which comprises an in-shaft directly driving one of said press rolls, an auxiliary shaft driven by i said in-shaft, an eddy current electric slip clutch having a driving part driven by said auxiliary shaft and a driven part adapted to bel driven by said driving part, a second in-shaft coupling the driven part of said clutch to another of said press rolls, said clutch having a coil associated therewith for inducing eddy currents between the driven and driving parts thereof, a direct current excitation circuit for energizing the coi1 of said clutch to induce eddy currents between the driving and driven parts thereof to drivingly couple said parts, and means for regulating the excitation of said coil to control the helper drive effort applied to said another of said press rolls from said one of said press rolls.

2. In a three roll horizontal press assembly for a paper machine including a rotatably mounted center roll, end rolls on each side of the center roll in pressure relation therewith for providing upward passage and downward passage nips, the improvement which comprises an in-ishaft coupled to one of said end rolls, means for directly driving -said ln-shaft, a second in-shaft coupled to the other of said end rolls, an electric dynamic slip clutch driving said second in-shaft, means coupling said first ln-shaft with said clutch to drive said second in-shaft through said clutch. said clutch having a coil associated therewith for inducing eddy currents between driven and driving parts thereof, a direct current energization circuit for said coil, and means for regulating current flow through said circuit for controlling slippage between the driven and driving clutch parts whereby any desired amount of helping enort can be applied from said first mentioned end roll to said last mentioned end roll.

LLOYD HORNBOSTEL 

